28 February 2017

HIV vaccine development continues

A new HIV vaccine has helped five patients fight the disease without medication

Daria Zagorskaya, Vesti

The reality is that in the scientific and especially medical community, the results of small clinical trials without the presence of control groups are mercilessly criticized and not taken seriously. More often than not, they are smashed to smithereens by deeper and more extensive research.

But when it comes to fighting the human immunodeficiency virus (HIV), even a modest positive result gives rise to hope of victory over this scourge of the modern world. This is especially true of the search for a vaccine, which over the past 30 years has yielded very few positive results.

From the latest encouraging news from the front line, we can recall the achievements of the team from the USA under the leadership of Dr. Michael Farzan. But the results of clinical trials of their drug have not yet been reported. Russian researchers also have promising developments.

And now, at the annual Conference on Retroviral and Opportunistic Infections held in Seattle (USA), scientists from Spain and the UK presented the results of clinical trials of their therapeutic vaccine against HIV (Mothe et al., Viral control induced by HIVconsv vaccines & romidepsin in early treated individuals). The name "therapeutic" means that the proposed drug does not serve to prevent infection with the virus, but to treat people who are already ill.

Let's explain. A person in whose body HIV has settled, and if it was detected at a relatively early stage, has to take so-called antiretroviral drugs (ARP) daily for the rest of his life. They allow you to stop the reproduction of the pathogen and prevent it from causing irreparable harm to the immune system. But it is completely impossible to exterminate it, because HIV is able to hide in cells and remain inactive until a favorable moment for it. As soon as the antiretroviral therapy is interrupted, the virus immediately begins to multiply actively and restores its position in the body after four weeks.

Despite the relative effectiveness of the treatment, it takes a lot of time, and ARPS are expensive and can lead to a number of severe side effects. The new strategy of therapeutic vaccination within the framework of complex therapy against HIV should minimize the consumption of ARP, as well as solve the problem of destroying viral "caches" in which the pathogen successfully hides from the immune system.

Two vaccines were developed by a group led by Thomas Hanke at Oxford University to implement the plan. Both of them carry genes that encode proteins peculiar to all varieties of HIV. When they get into the blood, they are recognized by the immune system as foreign agents and destroyed, and at the same time, virus-infected cells of the body fall under the scope.

Work with patients was started three years ago at the Spanish Institute for the Study of AIDS (IrsiCaixa). Researchers led by Beatriz Mothe selected 24 patients who were diagnosed with HIV no later than 6 months after infection. Each of them received a dose of the vaccine and started taking ARP.

By the second stage of therapy, 15 participants remained in the project, who on average received antiviral drugs for 3.2 years. Each of them was re-vaccinated with one of the vaccines.

The next step was the use of the initially anti-cancer drug romidepsin (romidepsin), which has already proven itself in the fight against the "caches" of HIV. It literally washes out the pathogen from the secluded places where it hides. Then the already prepared immune system is ready to tear apart any cell that shows signs of the presence of at least a particle of the virus.

After the sequential administration of three doses of romidepsin, the use of ARP by patients was completely stopped. For five of them, the new complex therapy worked exactly as the researchers expected, as they say in the press release IrsiCaixa A therapeutic HIV vaccine clinical trial induces viral control in 5 people without taking anti-retroviral therapy. The immune system of these patients independently continued to fight HIV for 6, 14, 19, 21 weeks and seven months, respectively.

Unfortunately, in ten cases, in order to contain the virus, it was soon necessary to return to the daily intake of traditional medicines. Now scientists are searching for possible reasons for the selective failure of the new treatment method.

Against the background of constant failures in the fight against HIV (when the virus returns again and again, even if it seemed that victory was won), the result of the team of Hanke and Moth seems impressive. Yes, they are forced to fend off criticism, including fair criticism, but the researchers continue to work, expect to significantly expand the range of patients in the future and take into account all the shortcomings of the pilot experiment.

Portal "Eternal youth" http://vechnayamolodost.ru  28.02.2017

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